(1) Field of the Invention
This invention relates to electronic probe devices and, more particularly, to electronic probe devices molded of conductive loaded resin-based materials comprising micron conductive powders, micron conductive fibers, or a combination thereof, homogenized within a base resin when molded. This manufacturing process yields a conductive part or material usable within the EMF or electronic spectrum(s).
(2) Description of the Prior Art
Electronic probe devices are used for providing electrical connectivity between electric signals, such as voltages and currents, in electrical circuits and measuring instruments, such as voltage meters and oscilloscopes. Electronic probe devices are constructed to provide a signal path having impedance and bandwidth characteristics optimized to the device under test (DUT) and to the testing instrument. For example, probes used in oscilloscope analysis typically have very high impedance such that the probe minimally disturbs the operating signal in the DUT. Conversely, a probe for an ohmmeter instrument has very low impedance such that a precise reading of a resistance value between a set of probes is possible. Other probe characteristics that are of concern in the art include matching the impedance of the probe path and the signal analyzer input, the effect of grounding connections and grounding loops, the effect of shielding in the probe and in cabling between the probe and the analyzing instrument, the effect of noise coupling, and the size and shape of probing contact points to the DUT.
Typically, electronic probe devices comprise metal for the probe contact points, signal path, and cabling. In addition, shielding structures in the probes and cabling typically comprise metal. Noise is easily coupled into prior art probe devices. This noise can interfere with accurate measurement and analysis of signal waveforms. A particular object of the present invention is to improve the noise cancellation of electronic probe devices.
Several prior art inventions relate to electronic probe devices. U.S. Pat. No. 5,574,769 to Clement teaches an inductive amplifier apparatus for detecting and amplifying an electrical tone conducted by one of a group of wires in order to identify and trace a particular wire and utilizes a probe tip comprising a conductive plastic. U.S. Pat. No. 6,706,554, B2 to Ogura teaches a method of probing semiconductor integrated circuit chips wherein the flat probe head comprises conductive resins or conductive plastics. U.S. Pat. No. 4,126,126 to Bare et al teaches a low cost electrode pad for used to detect biological or physiological electrical potentials in the human heart. This invention utilizes a non-conductive plastic coated with a conductive silver and silver chloride coating to render it conductive. U.S. Pat. No. 6,250,802 B1 to Dotan teaches an electronic thermometer with preheating capabilities that utilizes a (PTC) thermistor and a (NTC) thermistor embedded in a heat-conductive plastic comprising an epoxy resin and conductive particles and covered by an outer layer of an inert metal. U.S. patent application Ser. No. 2004/0095847 to Hassan et al teaches an apparatus and a method for measuring ultrasound drilling mud velocity. U.S. patent application Ser. No. 2004/0027129 to Cull teaches a subsurface pipeline inspection system. The system uses coils to transmit and to receive electromagnetic energy.